Re: [PATCH linux-2.6.12-rc6-mm1] blk: cfq_find_next_crq fix

From: Jens Axboe
Date: Thu Jun 16 2005 - 02:02:59 EST

On Thu, Jun 16 2005, Tejun Heo wrote:
> Hello, Jens.
> Hello, Andrew.
> In cfq_find_next_crq(), cfq tries to find the next request by
> choosing one of two requests before and after the current one.
> Currently, when choosing the next request, if there's no next request,
> the next candidate is NULL, resulting in selection of the previous
> request. This results in weird scheduling. Once we reach the end, we
> always seek backward.
> The correct behavior is using the first request as the next
> candidate. cfq_choose_req() already has logics for handling wrapped
> requests.

Good spotting, applied. I'll set up an iosched git tree as well, with a
cfq-ts branch.

Jens Axboe

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